Real Madrid midfielder Xabi Alonso has said he has full faith in whichever goalkeeper Jose Mourinho chooses for Wednesday's Copa del Rey home match against Celta Vigo.

Mourinho has yet to reveal whether he will recall club captain Iker Casillas for the game after Antonio Adan started Sunday's Primera Division clash with Real Sociedad but was sent off early for a professional foul.

Alonso, 31, said Real's players believed in both their senior goalkeepers and stressed that there were no personal problems between Mourinho and Casillas, who conceded three times as Madrid won Sunday's game 4-3.

Speaking as the players prepared for the Celta Vigo game, in which they must overcome a 2-1 first leg deficit to progress from the last 16, he said: "The team trusts as much in Iker as in Adan.

"The other day, Adan had the bad luck to be sent off in the sixth minute and Iker could do little about their goals.

"These are technical decisions [by Mourinho]. We back them completely. Iker seems fine to me. He is not used to being a substitute, but he is working hard to be ready for when it is his turn to play. With the boss, he has a respectful, cordial relationship."

Alonso said Celta would be tough test, adding that he hoped the Bernabeu crowd would help the home team progress.

"We know how important the game is," he said. "It is like a final for us. We hope that the team plays well and the fans support us. It is make or break for the Copa. We have to go out to win the game.

"Celta played well against Valladolid on Sunday, and we do not expect an easy game."

Speaking hours after attending Monday's FIFA Ballon D'Or ceremony in Zurich, during which he was named alongside club colleagues Iker Casillas, Sergio Ramos, Marcelo and Cristiano Ronaldo in the FIFPro Team of the Year, he said he understood Mourinho's decision not to travel to the event.

"Those of us who were at the FIFA gala yesterday enjoyed ourselves," he said. "The boss makes his own decisions. I asked him and he said he was working on the [Celta] game. He is very meticulous and professional."

As well as deciding which keeper to use, Mourinho's deliberations will have included some thinking about his defence.

Injured Portuguese pair Pepe and Fabio Coentrao are definitely out, but Sergio Ramos returns from suspension and both Raul Albiol and Marcelo have been back in full training with their colleagues in recent days, meaning at least two of the back four against Sociedad (Michael Essien, Ricardo Carvalho, Raphael Varane and Alvaro Arbeloa) may miss out.

The Portuguese coach could also make changes in midfield and attack, with Luka Modric, Angel Di Maria and Gonzalo Higuain all options to bring in after starting Sunday's game on the bench.

Alonso said he had not yet sat down to talk about extending his current deal with Madrid, which runs out in June 2014. "It is not something that bothers me because it is not even on the table," he explained.